Role of CD24 in anoikis resistance of ovarian cancer cells

This study examined the effect of CD24 on anoikis of ovarian cancer cells. The expression of CD24 was detected by RT-PCR and Western blotting in ovarian cancer cells with high metastatic potential (HO-8910PM cells) and low metastatic potential (A2780 cells). Cell viability and cell proliferation were detected by MTT assay in suspension culture and adhesion culture. Soft agar culture was used to observe the colony formation. Anoikis was flow cytometrically detected. The results showed that the expression levels of CD24 mRNA and protein were significantly higher in HO-8910PM cells than in A2780 cells (P < 0.01). In the suspension culture and soft agar culture, the HO-8910PM cells formed larger and more colonies (35.33 +/- 5.51 vs. 16.67 +/- 4.04; P < 0.01), and showed a stronger resistance to anoikis than A2780 cells did (cell apoptosis rate: 5.93%+/- 2.38% vs. 16.32%+/- 2.00%; P < 0.01). After treated with CD24 monoclonal antibodies, the number of colony formed in HO-8910PM and A2780 cells was significantly decreased (9.33 +/- 2.52 and 8.00 +/- 2.00, respectively), and the anoikis rate of the two cell lines was also markedly increased (23.11%+/- 2.87% and 28.36%+/- 2.29%, respectively). Our study suggested that CD24 may play an important role in the development of anoikis resistance and CD24 can be used as a new therapeutic target to induce anoikis and inhibit metastasis in ovarian cancer.